1. Field of the Invention
The present invention relates to a method for performing skin tests for allergic or other diagnostic reason. More particularly, the present invention relates to a method for loading a skin test device used for epicutaneous application of biological or test substances.
2. The Prior Art
Diagnosis of allergies has relied upon a number of techniques for introducing various biological substances to the epidermis or dermis. In a widely accepted testing method for allergies and other immunologic conditions--the skin test--various biologicals, such as aeroallergens, food allergens, and other substances are applied by abrading, cutting or puncturing the epidermal skin layer and contacting the liquid allergenic extract or the like with the exposed skin tissue. The test areas are often on the back or arm of the patient and the tests normally cause some discomfort. If the patient is allergic to a particular biological substance which is applied, histamine or a histamine substance will be released by the affected tissue resulting in redness and swelling in that area. The specific test sites are then compared to a control test site to visually determine if the patient is allergic to a particular test substance.
The skin tests may be performed one test at a time with each allergenic extract being loaded onto a scarifier or pick and applied to the skin. An example of a device for applying single tests is shown in U.S. Pat. No. 4,270,548. As it is desirable to speed up the testing process, devices for performing multiple tests simultaneously were developed. One such multiple skin test device which is widely used is the applicator disclosed in U.S. Pat. No. 3,556,080 to Hein which discloses a plastic applicator having an elongated handle from which extend curved connecting legs, each one of which terminates in a pressure puncture head having a cluster of sharp points. The method of using the Hein multi-headed applicator is to place the applicator upside down with the rigid handle being supported in a holder, such as described in Hein's U.S. Design Pat. No. 247,822. Each of the pressure puncture heads or picks is then individually loaded with a testing substance by the doctor or the nurse. Once the puncture heads are individually loaded, the applicator is grasped by the elongated handle and then applied to the skin in a manner that each puncture head can penetrate the surface of the skin. Using this method, loading each puncture head individually, takes a considerable amount of time.
An early form of a multi-headed skin test applicator is disclosed in U.S. Pat. No. 2,522,309 to Simon which discloses what is alleged to be the first simultaneous inoculation testing device. In the Simon patent the applicator comprises test covers (handles) having attached needles which are placed over a plurality of allergen containing wells in a manner to allow the needles to enter the fluid. The covers fit snugly over the wells in a sealing relationship. When the multi-headed applicator is removed from the wells with a spiral motion, the needles touch the sides of the wells to remove excess allogenic extract. The thus loaded multi-headed applicator is then used in the normal manner.
The desire to simplify and speed-up allergy testing procedures has led to the development of a number of other multi-headed skin test applicators. The patent to Galy, U.S. Pat. No. 4,453,926 provides a multi-headed scarifying device for simultaneously performing a plurality of skin tests. The device has a clustered group of points that are contained in a hermetically sealed envelope with the envelope containing an active liquid substance into which the cluster points are immersed. To operate the Galy device one must individually remove each envelope tab.
U.S. Pat. No. 3,289,670 to Krug, et al. describes a multi-headed device for simultaneously performing a plurality of scratches on a patent to apply biological testing substances. The device has a multi-well structure with a flat upper surface and a plurality of wells in the upper surface of the structure. The device also includes a reusable abrading unit having a skin abrading member with multiple cluster points which fit on top of the structure so the members fit into each well and are immersed in the liquid testing substance. When the tests are performed the multi-headed abrading unit is removed from the well and applied to the patient in the normal manner.
The present invention overcomes the disadvantages of the prior art by providing a method for rapidly loading a skin testing applicator with biologicals or other test substances.